Polyunsaturated higher fatty acids such as arachidonic acid serve in the metabolism of mammals, including man, as substrates for the formation of physiologically important eicosanoids such as prostaglandins and leucotrienes (a group of compounds also known as "Slow Reacting Substance of Anaphylaxis" or "SRS-A"). The pathway to prostaglandins is catalyzed by cyclooxygenase (also named "prostaglandin synthetase") whereas the pathway to leucotrienes is catalyzed by 5-lipoxygenase.
The prostaglandins are products having known beneficial functions in mammals. On the other hand, the leucotrienes or SRS-A, respectively, are known to cause allergic reactions, bronchoconstrictions, inflammations, asthma and numerous other harmful effects. Accordingly, there is a need for chemically and metabolically stable agents which in the living organism have no effect on the biosynthesis of prostaglandins but which selectively or specifically inhibit the activity of 5-lipoxygenase and thus prevent the formation of the undesired leucotrienes. However, up to now this problem has not yet been solved in an adequate manner.